Grip strength in different positions of elbow and shoulder

This study investigated the effect of shoulder position on grip strength in 80 men and 80 women. A Jamar dynamometer was used to measure the grip strength in the four testing positions. The four hand strength tests consisted of three positions in which the elbow was maintained in full extension combined with varying degrees of shoulder flexion (ie, 0 degrees, 90 degrees, and 180 degrees) and of one position in which the elbow was flexed at 90 degrees with the shoulder in 0 degrees of flexion. Only the dominant hand was tested. The highest mean grip strength measurement was recorded when the shoulder was positioned at 180 degrees of flexion with elbow in full extension; whereas the position of 90 degrees elbow flexion with shoulder in 0 degrees of flexion had the lowest grip strength score. In addition, the grip strength measured with the elbow in extension, regardless of shoulder position (ie, 0 degrees, 90 degrees, and 180 degrees of flexion), was significantly higher than when the elbow was flexed at 90 degrees with the shoulder positioned at 0 degrees of flexion. Finally, grip strength differed significantly for both sexes and for each age group. The grip values of the standardized 90 degrees elbow flexed position were further analyzed to determine the average performances in the study population. For men, grip strength peaked within the 20 to 39 years age group and gradually declined thereafter. For women, the highest mean grip strength measurement was recorded in the 40- to 49-year-old age group and then deteriorated with age.(ABSTRACT TRUNCATED AT 250 WORDS)